The use of waveguides for plane polarized feeds in microwave antennas causes degradation in the antenna radiation pattern due to the electromagnetic scattering effects of the outer surface of the waveguide on the radiation emitted from the aperture of the feed as well as the radiation reflected from the reflector surface. The results of poor radiation patterns include degraded antenna gain, cross-polarization, and undesirable directional coverage. These deleterious results apply in equal measure to antennas used for transmitting microwave radiation and to antennas used for receiving microwave radiation. These effects, in the past, have been mitigated by the use of microwave absorber on the waveguide bend surfaces. Problems associated with the use of absorber include an increase in the first few co-polarization side lobes due to the thickness of the absorber, long term weatherability issues, and the effects of moisture absorption by the microwave absorber.